简单的员工信息增删改查程序 表信息 1,Alex Li,22,13651054608,IT,2013‐04‐01 2,Jack Wang,28,13451024608,HR,2015‐01‐07 3,Rain Wang,21,13451054608,IT,2017‐04‐01 增加 add staff_table Alex Li,25,134435344,IT,2015-10-29 以phone做唯一键(即不允许表里有手机号重复的情况)，staff_id需自增 查询支持三种语法 find name,age from staff_table where age > 22 find * from staff_table where dept = "IT" find * from staff_table where enroll_date like "2013" 删除指定员工信息纪录 del from staff_table where dept = "IT" 更新记录 update staff_table set dept="Market" where dept = "IT" update staff_table set age=25 where name = "Alex Li"